Surgical retractors are often used in surgical procedures wherein relatively larger areas of access to surgical sites are required, and wherein retention and clearance of surrounding tissues is needed. A variety of surgical retractor assemblies are known in the art. Typically, retractor blades include stems which are secured or fastened to a frame which is positioned surrounding the surgical site.
The ability to position and secure retractor blades into fixed position or easily reposition or adjust the position during the surgical procedure has been a desirable feature in retractor assemblies. In certain surgical procedures, in addition to circumferential positioning of the retractor blades surrounding a surgical site, it is also advantageous to control the longitudinal adjustment of the retractor blade for opening and restraining tissue surrounding the surgical site. Even more advantageous is the ability to control the angle at which the retractor blades and stem are positioned relative to the surgical site and retractor support assembly, or relative “tilt angle”.
Adjustable surgical retractor mechanisms which attach to ring assemblies and permit longitudinal adjustment of the retractor blade stem as well as tilting adjustment are disclosed in Bookwalter et al. U.S. Pat. No. 4,424,724; Cabrera et al. U.S. Pat. No. 5,375,481 and Koros et al. U.S. Pat. No. Des. 397,791. The ratchet mechanisms described in Bookwalter et al. and Koros et al., however, permit separate longitudinal and tilting adjustments and require a certain degree of maneuvering and repositioning of the fingers and hands to operate. The mechanism described in Cabrera et al. operates such that actuation of one adjustment mechanism necessarily actuates another. None of these devices offer the practitioner the collective ability to individually or simultaneously adjust the tilt and/or longitudinal setting of the ratchet device in an ergonomically comfortable, non-awkward manner.
There exists a need in the medical field for improved retractor devices which permit the practitioner to freely and easily adjust and re-adjust the positioning of the retractor blade during a procedure in an accurate, non-awkward and non-cumbersome manner. There is a further need for surgical retractor assemblies and associated mechanisms to have improved ergonomic attributes.